Method, apparatus and system for detecting service data of a packet data connection

ABSTRACT

The invention relates to an apparatus, a system, a method and a computer program product for transmitting to a policy and/or charging server information relating to a user, wherein the information includes an indication of a service data detecting entity for detecting service data of a packet data connection of the user, and initiating communication towards the service data detecting entity based on the received information.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a mechanism for controlling acommunication connection. In particular, the present invention isrelated to a method, a system and apparatus for transmitting to a policyand/or charging server information indicating a service data detectingentity for detecting service data of a packet data connection.

BACKGROUND OF THE INVENTION

Policy control architecture has been defined by 3rd GenerationPartnership Project (3GPP). Policy elements can maintain information onactive packet connections of users and about packet gateways via whichthe packet connections traverse.

Traffic detection function (TDF), based on packet inspection, can beapplied in a network to support policy and charging control for servicesfor which the policy and charging control function (PCRF) does not getrelated service information from an application function (AF) or proxycall state control function (P-CSCF).

A standalone TDF is not able to identify the establishment of a packetdata connection, because the GPRS tunneling protocol (GTP) operatesbetween the PCEF and the access network and is consequently not seen bythe standalone TDF.

SUMMARY OF THE INVENTION

The present invention overcomes above drawbacks by providing anapparatus, a method and a computer program product comprisingestablishing a packet data connection for a user, and, transmitting to apolicy and/or charging server information relating to the user, whereinthe information can comprise an indication of a service data detectingentity for detecting service data of the packet data connection.

The information can comprise at least one of an internet protocoladdress of the user and an identity of the user. The indication cancomprise an address of the service data detecting entity (TDF).

The apparatus can be a packet data gateway and/or a policy enforcementfunction.

Further, an apparatus, a method and a computer program are providedcomprising receiving information relating to a user, wherein theinformation can comprise an indication of a service data detectingentity for detecting service data of a packet data connection of theuser, and, initiating communication towards the service data detectingentity based on the received information.

The information relating to the user can comprise at least one of aninternet protocol address of the user and an identity of the user andthe initiating can includes transmitting the information to the servicedata detecting entity (TDF).

The communication can comprise a control session for the user betweenthe service data detecting entity (TDF) and the apparatus, and thecontrol session can comprise receiving service information relating todetected service data of the packet data connection of the user.

The service information can comprise an indication on the start or thestop of the service.

The control session can comprise transmitting to the service datadetecting entity (TDF) instructions for detecting service data of thepacket data connection of the user

The communication can comprise transmitting a request to establish acontrol session for the user.

The communication can comprise transmitting to the service datadetecting entity (TDF) a contact address of the apparatus to enable theservice data detecting entity (TDF) to establish a control session forthe user based on the contact address.

Further, an apparatus, a method and a computer program are providedcomprising detecting service data of a packet data connection of a user,and, receiving from a policy and/or charging server (PCRF) a request toinitiate a control session for the user between the policy and/orcharging server (PCRF) and the apparatus, wherein the control sessioncan comprise reporting service information to the policy and/or chargingserver (PCRF) based on service data detected on the packet dataconnection of the user.

The request to initiate can comprise at least one of an internetprotocol address of the user, an identity of the user, instruction forservice detection, packet data connection identity and a contact addressof the policy and/or charging server (PCRF).

The service information can comprise an indication on the start or thestop of the service.

The request can comprise the policy and/or charging server (PCRF)establishing the control session with the apparatus, or, a request thatthe apparatus establish the control session with the policy and/orcharging server (PCRF).

The control session can comprise receiving from the policy and/orcharging server (PCRF) instructions for detecting service data of thepacket data connection of the user.

Further, a system, a method and a computer program are provided,comprising transmitting to a policy and/or charging server informationrelating to a user, wherein the information can comprise an indicationof a service data detecting entity for detecting service data of apacket data connection of the user, and transmitting, by the policyand/or charging server, to the indicated service data detecting entity arequest to initiate detection of service data of the packet dataconnection of the user.

The request and/or the information relating to the user can comprise atleast one of:

-   -   an internet protocol address of the user,    -   an identity of the user,    -   instruction for service detection,    -   packet data connection identity, and,    -   a contact address of the policy and/or charging server (PCRF).

The request can comprise a request to initiate a control session for theuser between the policy and/or charging server and the service datadetecting entity, and the control session can comprise reporting serviceinformation to the policy and/or charging server based on service datadetected on the packet data connection of the user.

The request can comprise the policy and/or charging server (PCRF)establishing the control session with the apparatus, or, a request thatservice data detecting entity is to establish the control session withthe policy and/or charging server (PCRF).

Embodiments of the present invention may have one or more of followingadvantages: The standalone TDF can recognize the attachment of the UEand establishment of an IP-CAN session/a default context in time beforethe actual user data transmission starts on the user plane, establish acontrol session with the PCRF and get service detection rules (SD rules)and possible policy rules (PCC rules), and thus avoid possible clippingof user data.

The standalone TDF is able to find the correct PCRF, i.e. the same PCRFas the PCEF (and BBERF, if applicable).

The standalone TDF can get additional information, like the UE IPaddress(es) and/or the user ID and PDN ID, which is essential e.g. forthe following operations:

To support multiple simultaneous PDN connections of the same UE, the PDNID is needed in addition to UE IP address/user ID to allow TDF toseparate different PDN sessions of the same UE.

In case there is NAT between PCEF and TDF, the UE's local and global IPaddress are needed in TDF. Local IP address may be needed for PCRFselection and global IP address is needed for traffic detection.

In most implementations the PCEF use UE ID for PCRF selection.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates Gx Reference model relevant for aspects of theinvention.

FIGS. 2 and 3 illustrate message flows according to aspects of theinvention.

FIG. 4 illustrates network elements, GTP and service data path relevantfor aspects of the invention.

FIG. 5 illustrates an example structure and functions of an apparatusesimplementing aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

IP-Connectivity Access Network (IP-CAN) refers to the collection ofnetwork entities and interfaces that provides the underlying IPtransport connectivity between the UE and the IMS entities. For example,a GPRS network can be used as an IP-connectivity access network.

IP flow is a unidirectional flow of IP packets with the same source IPaddress and port number and the same destination IP address and portnumber and the same transport protocol.

IP-CAN session is an association between a UE and an IP network. Theassociation can be identified by one or more UE IPv4 addresses/and/orIPv6 prefix together with a UE identity information, if available, and aPDN represented by a PDN ID (e.g. an access point name (APN)). An IP-CANsession can incorporate one or more IP-CAN bearers. Support for multipleIP-CAN bearers per IP-CAN session is IP-CAN specific. An IP-CAN sessionexists as long as the related UE IPv4 address and/or IPv6 prefix areassigned and announced to the IP network.

Serving GPRS support node (SGSN) is a GPRS support node in the IP-CANthat serves GPRS mobile stations by sending or receiving packets via abase station subsystem or a radio access network. SGSN is the basicelement of the GPRS infrastructure. It stores for each mobile in itscontext different parameters used to route the packets, for exampleinformation about the mobile's location.

Gateway GPRS support node (GGSN) acts as a gateway between the GPRSnetwork and packet-switched public data network (PSPDN). For thepacket-switched public data network, the GPRS network resembles asubnetwork which can transfer data to or from a GPRS mobile station. TheGGSN can hide the operation of the GPRS network from the packet-switchedpublic data network through the encapsulation of packets. From theexternal network's point of view, the gateway GPRS support node issimply a router to a subnetwork.

GPRS Tunneling Protocol (GTP) is a protocol that is used in the GPRS fortransmitting user data packets and signalling between GPRS support nodes(GGSN, SGSN) over GPRS backbone network.

Policy and charging rules function (PCRF) is a function that defines andprovides the policy and charging rules that are used in the policyenforcement points for policy control and flow-based charging control.The PCRF has been developed for the 3GPP Release 7 and it combines thecharging rules with the policy decision function of earlier 3GPParchitecture releases. PCRF can maintain IP-CAN session associated withusers.

Policy and charging enforcement function (PCEF) is a function thatreceives the policy and charging rules from the PCRF, detects traffic,and enforces the rules for classifying the traffic on service dataflows. The control for the quality of service (QoS) is applied perservice data flow in the PCEF. The PCEF can be co-located in a packetdata network (PDN) gateway.

Gx reference point is the reference point between a packet data network(PDN) gateway and a PCRF. The Gx reference point can be used to transferthe policy and charging information from the PCRF to the PCEF located inthe PDN gateway.

Policy and Charging Control (PCC) rules can be used to:

-   -   detect that a packet belongs to a service data flow.    -   downlink IP CAN bearers can be selected based on service data        flow filters within the PCC rule    -   Service data flow filters can be used for the enforcement that        uplink IP flows are transported in the correct IP CAN bearer.    -   identify a service to which the service data flow contributes        to.    -   provide charging parameters for a service data flow.    -   provide quality of service (QoS) and policy control for a        service data flow.

The PCEF can select a PCC rule for each received packet by evaluatingreceived packets against service data flow filters of PCC rules in theorder of the precedence of the PCC rules. When a packet matches aservice data flow filter, the packet matching process for that packetcan be completed, and the PCC rule for that filter shall be applied.

As part of PCC procedures, an IP-CAN session associated with an user canbe established. The PCRF can select a bearer control mode that willapply for the IP-CAN session and provide it to the PCEF via the Gxreference point.

The PCRF can indicate PCC rules to be applied at the PCEF in two waysover the Gx reference point:

-   1.) In pull procedure a PCC rule is requested by the PCEF. In    response to a request for PCC rules being made by the PCEF, the PCRF    can provision PCC rules, for example in a CC-Answer diameter    message.-   2.) In push procedure the PCRF can decide to provision PCC rules    without obtaining a request from the PCEF, for example, responsive    to information provided to the PCRF from an application function    (AF) over Rx reference point (FIG. 1), or based on an internal    trigger within the PCRF. When provisioning PCC rules without a    request from the PCEF, the PCRF can include the PCC rules in an    RA-Request Diameter message.

Bearer Binding and Event Reporting Function (BBERF) is a functionalelement located in an S-GW. It can provide control over the user planetraffic handling. The BBERF can be located in an access network (AN)gateway (GW).

Gateway Control Session is an association between a BBERF and a PCRF,used for transferring access specific parameters, BBERF events and QoSrules between the PCRF and BBERF.

Attribute-value pair (AVP) is a generic pair of values that consists ofan attribute header and the corresponding value. The AVP can be used toencapsulate protocol-specific data such as routing information, as wellas authentication, authorisation, or accounting information. Diameterprotocol can carry information using AVPs. Gx reference point cantransfer information using AVPs.

A PCEF and a PCRF can indicate supported features on the Gx referencepoint. Supported-Features AVP can be used during session establishmentto inform the destination host (PCEF/PCRF) about the required andoptional features that the origin host supports. The sender (client) canin the first request in a Diameter session indicate the set of featuresrequired for the successful processing of the session. If there arefeatures supported by the client that are not advertised as part of therequired set of features, the client can provide in the same requestthis set of optional features that are optional for the successfulprocessing of the session. The receiver of the first Supported-FeaturesAVP (server) can in the first answer within the Diameter sessionindicate the set of features that it has in common with the client andthat the server can support within the same Diameter session. Anyfurther command messages can be compliant with the list of supportedfeatures indicated in the Supported-Features AVPs and features that arenot indicated in the Supported-Features AVPs during sessionestablishment. Features that are not advertised as supported may not beused to construct the command messages for that Diameter session.

When there is no interaction between a policy function and anapplication and/or session level entity, such as application function(AF), the network may not be aware of the usage of a service by UE eventhough the network may have defined policies related to the service.User experience can be enhanced, if the network becomes aware of suchservices and the network is able to apply service specific policies.

Traffic detection function (TDF), based on deep packet inspection, canbe applied in a network to support policy and charging control (by PCRF)for services for which the PCRF does not get related service informationfrom an AF/P-CSCF. Such conditions may occur for example when the AFdoes not have an interface to the PCRF (refer to the Rx interfacebetween AF/P-CSCF and PCRF) or when there is no explicit service levelsignalling and hence no interaction between the AF and PCRF or whenfilters related to a service has not been installed in the PCEF.

The TDF can indicate the start and stop of the detected services to thePCRF. The PCRF can provision, modifies and/or delete PCC rules for thedetected service. The use of the service traffic detection mechanism maybe combined with privacy policies, in other words, the PCRF can checkupon an IP-CAN session establishment whether the use of the trafficdetection mechanism is allowed for a given user, and if yes, whichservices shall be monitored and detected. The PCRF can then instruct theTDF on which services it should detect and report.

Considering the traffic detection for policy and charging controlpurposes, the traffic detection functionality can be implemented eitheras co-located with PCEF or as a standalone entity. The standalonesolution can aim at avoiding performance and scalability problems thatmay occur in a solution where the traffic detection is integrated in thesame entity/gateway with the PCEF.

The use of the service traffic detection mechanism can requireuser/subscriber consent, and for this purpose the PCC architecture canbe extended to include user privacy policies (e.g. the PCRF can checkthe subscription data in a subscription profile repository (SPR) upon anIP-CAN session establishment, if the PCEF indicates the support of thetraffic detection function). Gx and Rx based interfaces can be used forthe interface between the PCRF and TDF.

When TDF and PCEF are collocated, the Gx based solution can be anextension to the current Gx interface/protocol and an Rx based solutioncan mean an extra Rx based protocol (in addition to Gx) between theTDF/PCEF and PCRF. A standalone TDF can mean a new (possibly Gx or Rxbased) protocol between the standalone TDF and PCRF.

Some policy enforcement related actions, for example, gating, shapingand redirection, can be activated at the TDF after the detection of agiven service. Normally these enforcement actions can be performed bythe PCEF.

A standalone TDF may not be able to identify the establishment of thedefault context/IP-CAN session, because the (GTP) protocol operatesbetween the PCEF and the access network and can consequently not be seenby the standalone TDF. The TDF can recognize the attach of the UE andestablishment of a default context only when the first applicationpacket is detected at the TDF. This can be too late for establishing acontrol session with the PCRF and too late for getting service detectionrules (and possible PCC rules) from the PCRF.

A standalone TDF is not able to find the correct PCRF, meaning the samePCRF as the PCEF (and BBERF, if applicable), because the TDF can not getall the required information from the detected application packets, i.e.the UE IP address(es) and/or the user ID and PDN ID.

Additional information can be needed for following reasons:

-   -   To support multiple simultaneous PDN connections of the same UE,        the PDN ID can be needed in addition to UE IP address/user ID to        allow the TDF to separate different PDN sessions of the same UE.    -   In case there is a network address translator (NAT) located        between the PCEF and the TDF, the UE's local and global IP        address can be needed in the TDF. The local IP address can be        needed for the PCRF selection and the global IP address can be        needed for the traffic detection.    -   The PCEF can use UE ID for the PCRF selection.

The PCEF can obtain this information upon the default context/IP-CANsession establishment.

FIGS. 1 and 4 show architecture and network elements relevant for policyand charging control. In FIG. 4, as can be seen, the GTP is establishedbetween the UE and the PCEF through the access network, however, the TDFis not involved in this and thereby cannot directly detect user planeactivity. Only later, when a first use plane packet is transmitted,shown as “service data” in FIG. 4, the TDF can detect user planeactivity. However, at this phase it can be too late for the TDF toestablish a control session and obtain instructions (rules) to detectservice traffic of the user since data is already transmitted.

According to an aspect of the invention, when a UE attaches the networkand a packet data connection default context is established between theUE and the P-GW/PCEF and the PCEF can establishes a (Diameter) controlsession to the PCRF, the PCEF can send an IP address/contact informationof the relevant TDF to the PCRF (in addition to the regular otherparameters like UE IP address and user ID, etc.).

According to an aspect of the invention, the PCRF can use the IPaddress/contact information of the TDF to contact the TDF for a controlsession establishment for the: identified user/UE.

According to an aspect of the invention, the PCRF can send the UE IPaddress(es), user ID, PDN ID and possibly other parameters to the TDF.The PCRF can also indicate the contact IP address the TDF can usetowards the PCRF. This information can be exchanged using acommon/auxiliary (Diameter) session, i.e. a (Diameter) session notdedicated to any specific user session.

A session can be established, for example, when the first need betweenthe PCRF and TDF appears or when the PCEF and TDF start up. Such asession can alternatively be established every time there is a need forit and deleted after that.

According to an aspect of the invention, the TDF can use the UE IPaddress(es), user ID, PDN ID and possible other parameters forestablishing a user/UE specific (Diameter) control session towards thePCRF that contacted the TDF.

With the information received from the PCRF, the TDF can operate in acurrently standardized way (standardized for PCEF, BBERF) as a Diameterclient, and the TDF can end up using the same PCRF as the PCEF.Consequently, an extended Gx protocol with minimal changes can beapplied to the interface between the TDF and the PCRF.

In the following, an example signalling flow is explained with help ofFIG. 2. In 201, a UE can attach the network and a default context (GTP)can be established between the UE and P-GW/PCEF. In 202, the PCEF canestablish a (Diameter) control session to the PCRF, the PCEF can sendthe IP address/contact information of the relevant TDF to the PCRF (inaddition to the regular other parameters like UE IP address and user ID,etc.). In 203, the PCRF can request the user profile from auser/subscription register (SPR). In 204, the PCRF can receive the userprofile from the register. The user profile can include e.g. servicedetection rules (SD Rules) to be used for traffic detection by the TDF.The user profile can include other parameters to be used for policydecision by the PCRF. In 205, the PCRF can make a policy decision, e.g.create PCC rules. In 206, the PCRF can send the PCC rules and possibleother parameters to the PCEF. In 207, the PCRF can make a decision torequest the TDF to establish a (Diameter) control session for theidentified user/UE. In 208, the PCRF can send to the identified TDF arequest for the TDF to establish a (Diameter) control session to thePCRF for the identified user/UE. In 209, the TDF can acknowledge therequest. On 210, the TDF can send a request (CC

Request) to establish a (Diameter) control session to the PCRF for theidentified user/UE. In 211, the PCRF can make a policy decision based onthe request and on the information retrieved earlier from the SPR forthe user. The policy decision can comprise SD rules, PCC rules andpossible other parameters. In 212, the PCRF can send the SD rules,possible PCC rules and possible other parameters to the TDF.

According to another aspect of the invention, the PCRF can operate as a(Diameter) client and can establish a user/UE specific (Diameter)control session towards the TDF. The PCRF can send service detectionrules and possible PCC rules (and other relevant parameters) in theinitial message/command to the TDF. This alternative does not requireany auxiliary session established by the PCRF towards the TDF, but onthe other hand, this solution changes the client vs. server roles of theTDF and PCRF.

In the following, an example signalling flow is explained with help ofFIG. 3. In 31, a UE can attach the network and a default context can beestablished between the UE and P-GW/PCEF. In 32, the PCEF can establisha (Diameter) control session to the PCRF, the PCEF sends the IPaddress/contact information of the relevant TDF to the PCRF (in additionto the regular other parameters like UE IP address and user ID, etc.).In 33, the PCRF can request the user profile from a user/subscriptionregister (SPR) and in 34 the PCRF can receive the user profile from theregister. The user profile can include e.g. service detection rules (SDRules) to be used for traffic detection by the TDF. The user profile mayinclude other parameters to be used for policy decision by the PCRF.

In 35, the PCRF can make a policy decision, e.g. create PCC rules. In36, the PCRF can send the PCC rules and possible other parameters to thePCEF. In 37, the PCRF can send a request (CC Request) to establish a(Diameter) control session to the TDF for the identified user/UE. Therequest may include SD rules, PCC rules and possible other parameters.In 38, the TDF can acknowledge the request.

According to an aspect of the invention, a PCEF/P-GW can send an IPaddress/contact information of a related TDF as a new parameter to thePCRF in the initial CC Request. PCRF can use the IP address/contactinformation of the TDF to establish a control session towards the TDF.

FIG. 5 illustrates an example internal structure and functions ofapparatuses implementing aspects of the invention. An apparatus 5, whichcan be a PCEF and/or a packet data gateway, has a packet data unit 51which can be configured to establish a packet data network (PDN)connection towards a UE. The PDN connection can be a PDP context,primary and/or default context and can be established according to GTPprotocol. The apparatus 5 can have storage unit 52 configured to storenetwork configuration information, for example addresses of variousnetwork elements. The storage unit 52 can store an indication (e.g. IPaddress) of a service data detecting entity 7, such as TDF 7, which canbe responsible for service traffic detection for users of the network. Apolicy unit 53 can be configured communicate with a policy server 6, forexample over Gx interface according to Diameter protocol. The policyunit 53 can perform various Qos, charging and policy related tasksindependently and/or based on instructions (PCC e.g. rules) receivedfrom the policy server 6. The policy unit 53 can decide to involve a TDF7 to monitor, analyze and/or detect service traffic of the UE on a PDNconnection established by the packet data unit 51. The policy unit 53can interface the storage unit 52 and can be configured to transmit theIP address of the TDF 7 to the policy server 6.

An apparatus 6, for example a policy server (PCRF), can have a policysignaling unit 61 configured to receive and transmit QoS, policy controland/or charging related information to and from another entity 5, forexample, to an from a packet data gateway 5. The policy signaling unit61 can operate over Gx interface according to Diameter protocol. Theapparatus 6 can have a rules unit 64 configured to maintain instructions(PCC rules) relating to QoS, charging and policy control. Theinstructions can be user specific. The rules unit 64 can be configuredto communicate with an external subscription repository (SPR) (shown inFIG. 1) to retrieve user specific information, for example subscriptionprofiles. The policy signaling unit 61 can instruct the packet datagateway 5 to control and enforce the UE connection according to PCCrules stored in the rules unit 64. The policy signaling unit 61 can beconfigured to receive an indication (IP address) of a service datadetecting entity 7, such as TDF 7, which can be responsible for servicetraffic detection for the connection established for the UE through thepacket data gateway 5 and the TDF 7. The apparatus 6 can have atransmitting unit 63 configured to transmit to the indicated TDF 7(based on the IP address received by the policy signaling unit 61) arequest that a service traffic of the UE can/should be detected. Thetransmitting unit 63 can also transmit other relevant information to theTDF 7 to enable service traffic detection to be initiated, for example,an identity of the user, IP addresses relating to the connection to bedetected, PDN ID etc, and/or an IP address of the apparatus 6 itself toallow the TDF 7 to establish a control session for traffic detectionwith the apparatus 6. A control session unit 62 can be configured toestablish a control session for service traffic detection with the TDF7. The control session unit 62 can receive from the TDF 7 information,for example events, relating to services detected on the service trafficof the user, for example, an indication of the start and/or stop of aspecific service. The control session unit 62 can transmit the receivedinformation to other units of the apparatus 6, and can store theinformation for later use. The control session unit 62 can be configuredto receive a request to establish a control session from the TDF 7.Alternatively or in addition, the control session unit 62 can beconfigured to transmit a request to the TDF 7 to initiate a controlsession. Alternatively or in addition, the transmitting unit 63 cantransmit a request to establish a control session when being in contactwith the TDF 7. The control session can be a Diameter session and thecontrol session unit 62 can be configured to act as a Diameter client orDiameter server depending on which element (PCRF 6, TDF 7) initiates thecontrol session.

An apparatus 7, for example a service data detecting entity 7, such asTDF 7, can have a traffic detection unit 72 configured to monitor,analyze and/or detect services in a packet data flow of a user. Thetraffic detection unit 72 can detect, for example, the start or stop ofa specific service based on characteristics of the data traffic. Thetraffic detection unit 72 can receive instructions, for example servicedetection rules and filters, on how to detect services from a controlsession unit 73, which in turn can be configured to received theinstruction from another apparatus (PCRF 6), for example during acontrol session or as a standalone signalling message. The apparatus 7can have a receiving unit 71 configured to receive information relatingto initiation of a control session with a PCRF 6. The information cancontain an IP address of the PCRF 6, identity of the user whose trafficis to be detected, necessary IP addresses to detect the traffic and/orPDN ID. The control session unit 73 can be configured to establish acontrol session for service traffic detection with the PCRF 6. Thecontrol session unit 73 can receive from the traffic detection unit 72information, for example events, relating to services detected on theservice traffic of the user, for example, an indication of the startand/or stop of a specific service which the control session unit 73 cantransmit to the PCRF 6. The control session unit 73 can be configured toreceive a request to establish a control session from the PCRF 6.Alternatively or in addition, the control session unit 73 can beconfigured to transmit a request to the PCRF 6 to initiate a controlsession. Alternatively or in addition, the receiving unit 71 can receivea request to establish a control session when being in contact with thePCRF 6. The control session can be a Diameter session and the controlsession unit 73 can be configured to act as a Diameter client orDiameter server depending on which element (PCRF 6, TDF 7) initiates thecontrol session.

All units described above in relation to FIG. 5 may be implemented forexample using microprocessors, chips and/or other electrical componentsand/or by software.

According to an aspect of the invention, a PCEF/P-GW indicates somelogical TDF identifier to a PCRF and the PCRF can map the identifier tothe real TDF address based on PCRF's internal mapping table.

According to an aspect of the invention, a PCEF/P-GW does not indicatethe TDF to a PCRF, but instead the PCRF performs the TDF selection andindicates the selected TDF with necessary address information back tothe PCEF/P-GW, based on which the PCEF/P-GW can route a PDN connectionof the user to the correct TDF.

According to an aspect of the invention, instead of GTP a Proxy MobileIP (PMIP) can be used. PMIT is a version of Mobile IP (MIP) that allowsthe movement of the mobility control from the mobile node to a proxy inthe network.

A packed data gateway establishing a packet data connection can be anytype of packet data node, for example, a PCEF/P-GW, GGSN, packet datagateway (PDG).

A packet gateway entity, service data determination entity and a policyentity may be physically implemented in a switch, router, server orother hardware platform or electronic equipment which can support datatransmission and processing tasks, or can be implemented as a componentof other existing device.

For the purpose of the present invention as described herein above, itshould be noted that

-   -   an access technology via which signaling is transferred to and        from a network element or node may be any technology by means of        which a node can access an access network (e.g. via a base        station or generally an access node). Any present or future        technology, such as WLAN (Wireless Local Access Network), WiMAX        (Worldwide Interoperability for Microwave Access), BlueTooth,        Infrared, and the like may be used; although the above        technologies are mostly wireless access technologies, e.g. in        different radio spectra, access technology in the sense of the        present invention implies also wirebound technologies, e.g. IP        based access technologies like cable networks or fixed lines but        also circuit switched access technologies; access technologies        may be distinguishable in at least two categories or access        domains such as packet switched and circuit switched, but the        existence of more than two access domains does not impede the        invention being applied thereto,    -   usable access networks may be any device, apparatus, unit or        means by which a station, entity or other user equipment may        connect to and/or utilize services offered by the access        network; such services include, among others, data and/or        (audio-) visual communication, data download etc.;    -   a user equipment may be any device, apparatus, unit or means by        which a system user or subscriber may experience services from        an access network, such as a mobile phone, personal digital        assistant PDA, or computer;    -   method steps likely to be implemented as software code portions        and being run using a processor at a network element or terminal        (as examples of devices, apparatuses and/or modules thereof, or        as examples of entities including apparatuses and/or modules        therefor), are software code independent and can be specified        using any known or future developed programming language as long        as the functionality defined by the method steps is preserved;    -   generally, any method step is suitable to be implemented as        software or by hardware without changing the idea of the        invention in terms of the functionality implemented;    -   method steps and/or devices, apparatuses, units or means likely        to be implemented as hardware components at a terminal or        network element, or any module(s) thereof, are hardware        independent and can be implemented using any known or future        developed hardware technology or any hybrids of these, such as        MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS        (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled        Logic), TTL (Transistor-Transistor Logic), etc., using for        example ASIC (Application Specific IC (Integrated Circuit))        components, FPGA (Field-programmable Gate Arrays) components,        CPLD (Complex Programmable Logic Device) components or DSP        (Digital Signal Processor) components; in addition, any method        steps and/or devices, units or means likely to be implemented as        software components may for example be based on any security        architecture capable e.g. of authentication, authorization,        keying and/or traffic protection;    -   devices, apparatuses, units or means can be implemented as        individual devices, apparatuses, units or means, but this does        not exclude that they are implemented in a distributed fashion        throughout the system, as long as the functionality of the        device, apparatus, unit or means is preserved,    -   an apparatus may be represented by a semiconductor chip, a        chipset, or a (hardware) module comprising such chip or chipset;        this, however, does not exclude the possibility that a        functionality of an apparatus or module, instead of being        hardware implemented, be implemented as software in a (software)        module such as a computer program or a computer program product        comprising executable software code portions for execution/being        run on a processor;    -   a device may be regarded as an apparatus or as an assembly of        more than one apparatus, whether functionally in cooperation        with each other or functionally independently of each other but        in a same device housing, for example.

The invention claimed is:
 1. An apparatus comprising: one or moreprocessors; and one or more memories including computer program code,the one or more memories and the computer program code configured, withthe one or more processors, to cause the apparatus to perform at leastthe following: establishing a packet data connection for a user,establishing a control session between a policy and/or charging serverfor the user packet data connection and the apparatus, transmitting tothe policy and/or charging server information relating to the user viathe established control session after establishing the user packet dataconnection, wherein the information comprises an address of a servicedata detecting entity for detecting service data of the packet dataconnection, and receiving a policy decision from the policy and/orcharging server.
 2. The apparatus of claim 1, wherein the informationfurther comprises at least one of an internet protocol address of theuser and an identity of the user.
 3. The apparatus of claim 1, whereinthe apparatus comprises at least one of a packet data gateway and apolicy enforcement function.
 4. An apparatus comprising: one or moreprocessors; and one or more memories including computer program code,the one or more memories and the computer program code configured, withthe one or more processors, to cause the apparatus to perform at leastthe following: establishing a control session between a policyenforcement function or a packet data gateway and the apparatus,receiving information relating to a user via the established controlsession from the policy enforcement function or the packet data gateway,wherein the information comprises an address of a service data detectingentity for detecting service data of an existing packet data connectionof the user, wherein the existing packet data connection is establishedbetween the user and the policy enforcement function or the packet datagateway, initiating communication towards the service data detectingentity based on the received information, and transmitting a policydecision to the policy enforcement function or the packet data gateway.5. The apparatus of claim 4, wherein the information relating to theuser further comprises at least one of an internet protocol address ofthe user and an identity of the user and wherein the information istransmitted to the service data detecting entity.
 6. The apparatus ofclaim 4, wherein the communication comprises a second control sessionfor the user between the service data detecting entity and theapparatus, wherein the second control session comprises receivingservice information relating to detected service data of the packet dataconnection of the user.
 7. The apparatus of claim 6, wherein the serviceinformation comprises an indication on the start or the stop of theservice.
 8. The apparatus of claim 6, wherein the second control sessioncomprises transmitting to the service data detecting entity instructionsfor detecting service data of the packet data connection of the user. 9.The apparatus of claim 4, wherein the communication comprisestransmitting a request to establish a second control session for theuser.
 10. The apparatus of claim 4, wherein the communication comprisestransmitting to the service data detecting entity a contact address ofthe apparatus to enable the service data detecting entity to establish asecond control session for the user based on the contact address.
 11. Amethod comprising: establishing a control session between a policyenforcement function or a packet data gateway and a policy and/orcharging server, transmitting, by the policy enforcement function or thepacket data gateway, to the policy and/or charging server informationrelating to a user via the established control session, wherein theinformation comprises an address of a service data detecting entity fordetecting service data of an existing packet data connection of theuser, wherein the existing packet data connection is established betweenthe user and the policy enforcement function or the packet data gateway,and transmitting, by the policy and/or charging server, to the indicatedservice data detecting entity a request to initiate detection of servicedata of the existing packet data connection of the user; wherein themethod further comprises: transmitting, by the policy and/or chargingserver, a policy decision to the policy enforcement function or thepacket data gateway.
 12. The method of claim 11, wherein at least one ofthe request and the information relating to the user comprises at leastone of: an internet protocol address of the user, an identity of theuser, instruction for service detection, packet data connectionidentity, and a contact address of the policy and/or charging server.13. The method of claim 11, wherein the request comprises a request toinitiate a second control session for the user between the policy and/orcharging server and the service data detecting entity, and wherein thesecond control session comprises reporting service information to thepolicy and/or charging server based on service data detected on thepacket data connection of the user.
 14. The method of claim 11, whereinthe request comprises the policy and/or charging server establishing asecond control session with the service data detecting entity, or arequest that the service data detecting entity is to establish a secondcontrol session with the policy and/or charging server.
 15. A computerprogram product comprising a non-transitory computer-readable storagemedium bearing computer program code embodied therein for use with acomputer, the computer program code comprising code for performing themethod of claim
 11. 16. A method comprising: establishing a packet dataconnection for a user, wherein the packet data connection is establishedbetween the user and a policy enforcement function or a packet datagateway, and establishing a control session between the policyenforcement function or the packet data gateway and a policy and/orcharging server, transmitting, by the policy enforcement function or thepacket data gateway, to the policy and/or charging server via theestablished control session after establishing the user packet dataconnection, information relating to the user, wherein the informationcomprises an address of a service data detecting entity for detectingservice data of the packet data connection; wherein the method furthercomprises: receiving, by the policy enforcement function or the packetdata gateway, a policy decision from the policy and/or charging server.17. A method comprising: establishing a control session between a policyand/or charging enforcement function or a packet data gateway and apolicy and/or charging server, receiving, by the policy and/or chargingserver, information relating to a user via the established controlsession from the policy enforcement function or the packet data gateway,wherein the information comprises an address of a service data detectingentity for detecting service data of an existing packet data connectionof the user, wherein the existing packet data connection is establishedbetween the user and the policy enforcement function or the packet datagateway, and initiating, by the policy and/or charging server,communication towards the service data detecting entity based on thereceived information; wherein the method further comprises:transmitting, by the policy and/or charging server, a policy decision tothe policy enforcement function or the packet data gateway.
 18. A systemcomprising: a packet data entity configured to transmit to a policyand/or charging server information relating to a user, wherein theinformation comprises an address of a service data detecting entity fordetecting service data of an existing packet data connection of theuser, wherein the existing packet data connection is established betweenthe user and the packet data entity, the policy and/or charging serverbeing configured to transmit to the indicated service data detectingentity a request to initiate detection of service data of the existingpacket data connection of the user, the policy and/or charging serverbeing further configured to make a policy decision and to transmit thepolicy decision to the packet data entity, and the service datadetecting entity being configured to detect service data of theexisiting packet data connection of the user.